Two Stroke Internal Combustion Engine. Patent of Russian Federation No. 2143077, Int. Cl. F02 B 33/00, registered Dec. 20, 1999, published in 1999, Bul. No 35, priority date Jun. 22, 1998, application No 98111885/06.
1. Two Stroke Internal Combustion Engine. RU Patent No. 2063524, Int. Cl. F02 B 33/22, published in 1996, Bul. No. 19.
2. Two Stroke Internal Combustion Engine. U.S. Pat. No. 2,522,649, US Cl. 123-70, 1950.
3. Radial Two Stroke Internal Combustion Engine with Piston Scavenging Pumps. SU Patent No. 54112, Int. Cl. F02 B 33/22, 75-22, 1939.
1. RU Patent No. 2063524 Cl, Jul. 10, 1996
2. U.S. Pat. No. 2,522,649 A, Sep. 19, 1950
3. SU Patent No. 54112 A, Feb. 28, 1939
4. SU Patent No. 2472 A, Mar. 31, 1927
5. U.S. Pat. No. 3,880,126 A, Apr. 29, 1975
6. U.S. Pat. No. 5,265,564 A, Nov. 30, 1993
7. GB Patent No. 994371 A, Nov. 7, 1961
This invention relates to further development of two stroke internal combustion engines (from hereinafter referred to as xe2x80x98TSICExe2x80x99), which have one or more power cylinders with intake and exhaust ports, and a source of scavenging of the power cylinders.
Some terms and abbreviations used in the following description of previous art and present invention are defined below.
Pistons of TSICE move reciprocally within two limits, conventionally named as xe2x80x98top dead centerxe2x80x99 and xe2x80x98bottom dead centerxe2x80x99. From hereinafter top dead center is referred to as xe2x80x98TDCxe2x80x99 and bottom dead center as xe2x80x98BDCxe2x80x99.
Cavity of a cylinder, which is a space within the walls of the cylinder limited by a face of a piston, from hereinafter is referred to as xe2x80x98cavityxe2x80x99.
In a double-sided cylinder, a piston has two faces, front and rear, which form two cavities within the walls of the cylinder on the opposite sides of the piston. In further description, due to the upright position of the cylinders on the drawings, the said cavities are referred to as xe2x80x98upper cavityxe2x80x99 and xe2x80x98lower cavityxe2x80x99.
The main problems, known as deficiencies of TSICE, are the partial mixing of burned gases with the fresh air-fuel mixture, and the loss of some fresh air-fuel mixture through the exhaust ports at the time of scavenging.
As long as improvements can be achieved, reducing these problems, there is a chance to increase power per liter of displacement.
The so-called direct-flow scavenging/charging of the power cylinders has to be organized, when fresh air-fuel mixture fills up the cavity of the power cylinder starting from the intake port towards the exhaust port, so that burned gases always remain in the way of the air-fuel mixture to the exhaust port with minimum mixing.
One of the ways to achieve direct-flow scavenging/charging is to have two power cylinders, connected to each other with a common combustion chamber, where one of the cylinders has an intake port, and another has the exhaust port, as it is in RU Patent No. 2,063,524. Scavenging/charging starts in one cylinder and ends in the other, most importantly, cleaning the area of combustion chamber of burned gases and providing unidirectional displacement of burned gases with fresh air-fuel mixture.
TSICE, according to RU Patent No. 2,063,524, uses a pumping cylinder as a source of scavenging/charging of power cylinders. It comprises the first power cylinder with an intake port, connected to a pumping cylinder, and the second power cylinder with an exhaust port, said cylinders having a common combustion chamber and pistons connected each to its own crank, with the crank of the second piston having advanced crank angle against the crank of the first piston, enabling advanced opening and closing of the exhaust port in relation to the intake port.
Use of an additional cylinder, piston and crank solely for the purpose of scavenging/charging of another cylinder, increases the size and weight of the engine and reduces power per liter of displacement, and should be considered a drawback of the above named patent.
According to the totality of distinctive characteristics, the engine construction of RU Patent No. 2,063,524 is considered the closest prototype of present invention.
Presented is TSICE, which has double-sided cylinders with upper and lower cavities used as power or pumping cavities, connected to each other in different combinations, which reduces the number of cranks and pistons and size and weight of the engine and increases power per liter of displacement.